<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script type="text/javascript" src="../js/vue.js"></script>
</head>

<body>
    <div id="root">
        <h2>今天天气很{{info}}</h2>
        <button @click="changeWeather">切换天气</button>
        <hr />
        <h3>a的值是:{{numbers.a}}</h3>
        <button @click="numbers.a++">点我让a+1</button>
    </div>
    <script type="text/javascript">
        const vm = new Vue({
            el: '#root',
            data: {
                isHot: true,
                numbers: {
                    a: 1,
                    b: 1
                }
            },
            computed: {
                info() {
                    return this.isHot ? '炎热' : '凉爽'
                }
            },
            methods: {
                changeWeather() {
                    this.isHot = !this.isHot;
                }
            },
            watch: {
                isHot: {
                    handler(newValue, oldValue) {
                        console.log('isHot被修改了', newValue, oldValue)
                    }
                },
                numbers: {
                    deep: true,
                    handler(newValue, oldValue) {
                        console.log('a被修改了', newValue, oldValue)
                    }
                }
            }
        })
    </script>

</body>

</html>